A sorting device sorts objects based on sorting information such as addresses. For example, in sorting processing (sorting session), the sorting device obtains object images including sorting information such as characters or codes, recognizes the sorting information included in the obtained images, and sorts the objects based on the sorting information obtained as a recognition result. The sorting device performs sorting processing (sorting session) a plurality of times on individual objects to precisely sort the objects. In first sorting processing, the sorting device prints identification information (e.g. barcodes) on objects, associates and stores the printed identification information and sorting information read from the objects, and sorts the objects based on the sorting information. In second and subsequent sorting processing, the sorting device specifies the sorting information of the object based on the printed identification information, and sorts the object based on the specified sorting information.
However, there is a problem that it is necessary to provide a printing mechanism to the sorting device to print identification information on objects, and it is difficult to print identification information depending on object shapes and properties.